China
Africa
Explore chapters and articles related to this topic
Nuclear Power
Published in Robert Ehrlich, Harold A. Geller, John R. Cressman, Renewable Energy, 2023
Robert Ehrlich, Harold A. Geller, John R. Cressman
You may be wondering under which conditions a proton is transformed into a neutron and when the reverse occurs in the cases of beta± decays. Nuclei spontaneously tend to transform themselves from less stable states to more stable states. In general, the most stable nuclei having a given mass number A tend to have a specific neutron–proton ratio, which is 50/50 (N = Z) for light nuclei, i.e., up to around Z = 20, and favoring neutrons (N > Z) to an increasing degree for heavier nuclei. These most stable nuclei lie along the “valley of stability”—the red (black) region in Figure 3.5. Beta-plus decay (changing a proton into a neutron) occurs when a particular isotope is above and to the left of the valley of stability, as they are too proton-rich, and conversely beta-minus decay (changing a neutron into a proton) occurs when a particular isotope is below or to the right of it.
Nuclear Power
Published in Robert Ehrlich, Harold A. Geller, Renewable Energy, 2017
Robert Ehrlich, Harold A. Geller
You may be wondering under which conditions a proton is transformed into a neutron and when the reverse occurs in the cases of beta± decays. Nuclei spontaneously tend to transform themselves from less stable states to more stable states. In general, the most stable nuclei having a given mass number A tend to have a specific neutron–proton ratio, which is 50/50 (N = Z) for light nuclei, i.e., up to around Z = 20, and favoring neutrons (N > Z) to an increasing degree for heavier nuclei. These most stable nuclei lie along the “valley of stability”—the red (black) region in Figure 3.5. Beta-plus decay (changing a proton into a neutron) occurs when a particular isotope is above and to the left of the valley of stability, as they are too proton-rich, and conversely beta-minus decay (changing a neutron into a proton) occurs when a particular isotope is below or to the right of it.
Mechanism of Fission Neutron Emission: New Experimental Arguments
Published in Nuclear Science and Engineering, 2020
Fission fragments are on the neutron-rich side of the valley of stability. In the case of fission neutron emission, model parameters (level density) should be corrected taking into account this physical effect if the level density parameters are lower for nuclei off the valley of stability. One may expect the reduction of the level density may improve the agreement between experimental and calculated results in the energy range E > 2 MeV.